Investigations into doping allegations against seven-times Tour de France winner Lance Armstrong will continue into the New Year, World Anti-Doping Agency (WADA) president Dick Pound said.
"It's not going to go away," Pound told Reuters. "We're dealing with all the spins out there right now but behind scenes there are investigations quietly proceeding.
"There is no urgency because he is not going to be in another race but there are some explanations that have to be given."
After Armstrong's seventh Tour victory last July the French sports daily L'Equipe published a story alleging Armstrong had taken the banned blood booster EPO (erythropoietin) in 1999.
Armstrong, 34, who retired after the race, has denied ever taking performance-enhancing drugs.
In the interview, Pound was also critical of the role played by the International Cycling Union (UCI).
"The UCI says it is conducting an investigation, although we can't seem to get information about it, and we are doing our own," said Pound.
"I'd rather have the UCI do it, by all accounts they should. If they do a complete and thorough investigation, more power to them. But I'm not overly confident so far. Right now the only thing they seem concerned about is how did this embarrassing information get into the public.
"And there are another 15 or so positive tests on which they refuse to comment."
L'Equipe's report said the newspaper had gained access to laboratory documents which reported that six of Armstrong's urine samples collected on the 1999 Tour showed "indisputable" traces of EPO.
The newspaper published what it said was a results sheet from the laboratory which appeared to show six figures revealing traces of EPO. The newspaper also published documents from the French cycling federation showing exactly the same figures under Armstrong's name.
Investigations into the allegation, however, soon stalled as WADA, the UCI and the French cycling federation engaged in a bitter public debate on how to proceed.
Armstrong, who overcame testicular cancer to become the most successful rider in cycling history, briefly threatened to return to France to race in one more Tour.
But he said in a recent interview that, "race organisers can sleep peacefully, they won't have to look at Armstrong eye to eye".
Armstrong, however, will be making an appearance in an Italian court in March when he will go on trial for defamation, a charge that carries a maximum six-year prison sentence.
The charge stems from another interview Armstrong gave to the French daily Le Monde in which he called fellow rider Filippo Simeoni a liar. Italy's Simeoni gave evidence in 2002 during the trial of Armstrong's former coach Michele Ferrari saying that the latter had given him doping substances.